I have a 1993 Cobra with 42,000 miles. I got the car from the original owner in Indiana. The car is nowhere near stock and has had a lot of work done to it over the years. It was a twin turbo'd 347 for a long time, but when I bought it was back to the naturally aspirated 347 setup. Its a really nice car, but it was a weekend driver/track car for the previous owner so it hasn't been babied...

When I got the car in a trade I got it knowing that it had a couple issues I needed to work out. When I got it home last year it would barely crank and when it did, it ran like crap.. I checked the codes and the car was missing the ECT sensor, had a couple grounds that were loose, bad MAF, etc... I fixed all the codes that is was showing and got a new Pro M meter and injectors. By this time the car was running great except for the high rpm miss under load.. So I quit chasing this problem and concentrated on other things with the car.

Its been over a year now, and I have been working on the car almost non stop with different projects over the months. Now it runs great in every aspect except for cruising at a constant speed in high gear I can still feel a random miss every now and then and it sometimes stutters under WOT pretty bad. It seems like the problem shows up/gets worse when the car warms up.. I have read a lot and tested most things that I know how to do so far. Here is a list of what I have done so far:

Timing set to 16*Fuel pressure is set to 42# and holds constant under load. Spark plugs are new and are gapped to 0.040"Spark plug wires are new Ford racing and are not arcing to anything that I can see.Cap and rotor are in good shape. TFI has been replacedValves are set to 1/4 turn past zero lashTested for vacuum leaks and none are present.EGR has been deleted completely with EGR delete plug. Pro M MAF meter cal'd to 42# injectors (Car has A9P processor) The car has an externally mounted 255 LPH fuel pump with braided fuel hose all the way to the fuel rail.

The car is not showing a CEL, and the only codes it is giving have to do with emissions stuff that I have deleted. It runs and drives great right now, except for a light miss cruising at low rpm, and the stutter under WOT.. Sometimes it screams like it should, and sometimes it stutters so bad that it doesn't accelerate very well at all...

HELP!!!! I don't know what else to check!!! Car idles great, drives great, everything is good except the intermittent miss that appears while cruising/hard accelerating when the car warms up..

The right to be stupid is inalienable for sure however, there is no such thing as a right to impose stupidity onto othersGreat Thoughts will Overwhelm a Feeble MindThere is never money to do it right, but there's always money to do it over.Knowledge based on external evidence is unreliable.He, who doesn't ask, does not deserve an answer.A mind is like a parachute it only works when it is open. (oldmanjoe)If you can't explain it simply, you don't understand it well enough. (Albert Einstein)Tuning on a Dyno for the track, is like swim practice in a bathtub.I can explain it for you, but I can't understand it for you. (90lxcoupe)The proof of understanding is the ability to explain it. (H. Torruella)Ignorance is bliss, but stupidity is orgasmic.Fraud and falsehood only dread examination. Truth invites it. (Samuel Johnson) The chaotic resistance of the opponents leads to the conclusion that they are not prepared to meet the challenge. The problem is already much more psychological then technological. [Bojidar Djordjev]Individuals are rational and humane... Crowds are reactionary and barbaric. (Jason)The person who says it cannot be done should not interrupt the person doing it. –Chinese ProverbNothing sways the stupid more than arguments they can't understand - Cardinal de Retz

Well the Ford TFI is still on the stock distributor, I have tried different distributor/TFI combo and the same problem still exists... But I did swap coil wires and the problem seems to be better/fixed... I drove it 100 miles Friday night and it ran pretty good, still has a slight miss at cruising speeds, but the stumble under WOT is gone!!?!? I think.....

this sounds like the same problem i once had. My problem was due to the spark plug wires being routed nice and neatly. The spark was jumping across wires due to the firing order and the proximity of plug wires to each other. The fix was to replace the wires and plugs,,,,,,,,(the problem ruined a brand new set) and to re-route the wires all crappy looking (away from each other). Maybe Joel remembers the Ford service bulletin??? Its an easy fix and cant hurt to try.

Well I am hoping that this was the issue and it is resolved, but I guess time will tell.. This car had the black Ford racing wires that look brand new, so I never even thought twice about them being the culprit. Then I noticed that the coil wire was a different brand/size wire than the rest of them. Replaced it with an MSD 8.5mm wire I had laying around, and it seems to have fixed it. I ordered a new set of black MSD super conductor wires that will be here in a day or so. I'll report back with the verdict if this solved it or not.

But the car still has another issue that I cant figure out, I had forgot to mention it until now. When the car sits overnight or for an extended period of time, and you crank it up... It ALWAYS goes dead within the first2 seconds of cranking it.. The second time you fire it up it'll run great, but it always dies the first time.. I have no idea what that means and its kinda annoying, but its not a huge problem... But if it is related to my ongoing issue I would like to figure it out as well.

Well, new plug wires didn't fix my issue. Its still there just like it always has been.

One thing I have noticed lately is that I have to cycle the key on and off 4 or 5 times before the fuel pump primes up??? Not sure what that is all about. I have a fuel pressure gauge on the cowl, and it takes quite a while for it to build pressure. But once it primes then it cranks and runs normally.. But "normally" with this car means, intermittent sputtering under load... Not sure what else to change out/test at this point.

The right to be stupid is inalienable for sure however, there is no such thing as a right to impose stupidity onto othersGreat Thoughts will Overwhelm a Feeble MindThere is never money to do it right, but there's always money to do it over.Knowledge based on external evidence is unreliable.He, who doesn't ask, does not deserve an answer.A mind is like a parachute it only works when it is open. (oldmanjoe)If you can't explain it simply, you don't understand it well enough. (Albert Einstein)Tuning on a Dyno for the track, is like swim practice in a bathtub.I can explain it for you, but I can't understand it for you. (90lxcoupe)The proof of understanding is the ability to explain it. (H. Torruella)Ignorance is bliss, but stupidity is orgasmic.Fraud and falsehood only dread examination. Truth invites it. (Samuel Johnson) The chaotic resistance of the opponents leads to the conclusion that they are not prepared to meet the challenge. The problem is already much more psychological then technological. [Bojidar Djordjev]Individuals are rational and humane... Crowds are reactionary and barbaric. (Jason)The person who says it cannot be done should not interrupt the person doing it. –Chinese ProverbNothing sways the stupid more than arguments they can't understand - Cardinal de Retz

I did run codes again this past weekend. The only codes that it threw were for the secondary air injection and charcoal canister.. I recently installed the EGR bypass plug so it doesn't throw that code anymore. I still haven't passed a cylinder balance test with this car, but every time I run it it gives a different cylinder number. Sometimes 2 cylinders.

FWIW my high RPM miss was fixed by a new distributor. Even though I previously put all new electronics on my factory distributor and cleaned it up. If both distributors you tried were OEM I wouldn't rule that out as the cause yet.

I still have the OEM dizzy, but I also bought a parts store Richporter Tech. dizzy and there is no difference in performance. Has the same miss/studder with both distributors. I am starting to think it could be related to fuel delivery.. It never loses pressure on my gauge though. I am stumped..

The right to be stupid is inalienable for sure however, there is no such thing as a right to impose stupidity onto othersGreat Thoughts will Overwhelm a Feeble MindThere is never money to do it right, but there's always money to do it over.Knowledge based on external evidence is unreliable.He, who doesn't ask, does not deserve an answer.A mind is like a parachute it only works when it is open. (oldmanjoe)If you can't explain it simply, you don't understand it well enough. (Albert Einstein)Tuning on a Dyno for the track, is like swim practice in a bathtub.I can explain it for you, but I can't understand it for you. (90lxcoupe)The proof of understanding is the ability to explain it. (H. Torruella)Ignorance is bliss, but stupidity is orgasmic.Fraud and falsehood only dread examination. Truth invites it. (Samuel Johnson) The chaotic resistance of the opponents leads to the conclusion that they are not prepared to meet the challenge. The problem is already much more psychological then technological. [Bojidar Djordjev]Individuals are rational and humane... Crowds are reactionary and barbaric. (Jason)The person who says it cannot be done should not interrupt the person doing it. –Chinese ProverbNothing sways the stupid more than arguments they can't understand - Cardinal de Retz